The present invention relates generally to an energy management system for placement in different portions or structural cavities of an occupant transportation vehicle for the management, direction, and absorption of energy. More particularly, the present invention relates to a reinforcing energy management structure for use in an automotive rail, such as a frame, front rail, or other chosen portion of an automotive vehicle, which can be selectively tuned or targeted to help absorb, direct, and/or transfer energy in the vehicle body.
For many years the transportation industry has been concerned with designing structural members that do not add significantly to the weight of a vehicle. At the same time, automotive applications require structural members capable of providing reinforcement to targeted portions of the vehicle and permit ingress and egress to the passenger compartment in the event of a collision or other impact event. While the devices found in the prior art may be advantageous in many applications, the prior art methods typically require the use of additional manufacturing processes and steps in either a supplier facility, a pre-production manufacturer stamping facility, or the final vehicle assembly planet which often increases labor demand, cycle time, capital expense, and/or required maintenance clean-up. Accordingly, there is needed a simple, low cost structure or system for reinforcing vehicle rails, such as a front rail or frame member, which reinforces the vehicle, enhances structural integrity, and can be efficiently incorporated into the vehicle manufacturing process. In addition, there is also a need for a relatively low cost system or structure which provides reinforcement and inhibits distortion to the frame or front rail structures in a vehicle, and which can serve to manage energy in a frontal/offset impact to the vehicle by reinforcing the frame member or front rail to help target applied loads and help redirect or tune energy management of deformation.
The object of the present invention is to redirect applied loads and manage impact energy by placing a reinforcement system in targeted areas of an automotive rail, frame member, or other portion of a vehicle. The system generally employs at least one member or insert, which is attached or adhered to the chosen portion of the vehicle such as a frame or rail or any other portion of an automotive vehicle selected to inhibit deformation in the event of impact to the vehicle. The member may also comprise a plurality of members suitable for receiving an application of an expandable or non-expandable reinforcing material coated, disposed, or placed over at least a portion of an exterior surface of the member or members. The reinforcing material disposed on the member is capable of activation when exposed to heat typically encountered in an automotive paint operation, such as e-coat and other paint cycles in a vehicle assembly plant. It is contemplated that the reinforcing material disclosed in the present invention, activates, optionally expands, and then adheres, cures, or bonds thereby structurally reinforcing and enhancing the strength and stiffness of the frame or front rail to redirect applied loads and energy. In one embodiment, the material is heat expandable and at least partially fills a cavity defined by the rail, frame, or selected portion of the vehicle by structurally adhering the rail and the frame depending upon the size and shape of the cavity, during the e-coat bake operation. In another embodiment, the reinforcing material is a melt flowable material comprising one or more components, which upon the application of heat will spread over a surface. The selected reinforcing material may also provide a variety of characteristics including structural reinforcement, stress-strain reduction, vibrational damping, noise reduction, or any combination thereof. In an alternative embodiment, the reinforcing material may be non-expandable or otherwise suitable for filling a defined volume or space within the selected insert or member.
In a particular preferred embodiment, the present invention further serves to manage crash energy typically encountered during frontal impact testing of an automotive vehicle. More specifically, the member or insert of the present invention may contain at least one and preferably a plurality of triggers consisting of notches, holes, or any other form of step change or alteration to the geometry of an internal or inner portion or portions of the member. The internal triggers of the present invention effectively target and direct axial bending to selected portions of the system and allow management of crash energy typically encountered during front offset testing. The system of the present invention further comprises a reinforcing or bonding material disposed over at least a portion of the member which can be extruded, molded, or xe2x80x9cmini-applicationxe2x80x9d bonded onto the member in either a pre-production setting, such as a stamping facility, or during the final assembly operation. The member, and the selected bonding or expandable material, is installed in the selected frame or rail prior to the e-coat or paint operation processing. Hence, the present invention provides flexibility in the manufacturing process since it can be utilized by either the frame or front rail manufacturer/supplier or the final vehicle manufacturer with reduced labor, capitol expense, maintenance requirements, and floor space demand. Once the reinfocing material bonds and cures to the selected rail or frame portion of the vehicle, distortion of the frame or front rail may be inhibited or managed during a frontal/offset impact event or any other application of impact energy to the exterior of the vehicle. By absorbing and/or transferring certain impact energy and providing reinforcement to the frame or rail portion of the vehicle, the present invention provides a system for managing deformation to the vehicle in the event of a frontal/offset impact.